1. Field of the Invention
The present invention relates to an IC card and other electronic devices having a contact-type interface and a non-contact-type interface as a communication interface for communication with external devices such as card reader-writer.
2. Description of the Related Art
The magnetic card has found a variety of uses such as the credit card, the cash card and the commutation ticket. The IC (integrated circuit) card is superior to the magnetic card with regard to memory capacity for information, safety of information, or the like. But in Japan, the IC card has not been used widely yet. One of the reasons for that is its high cost as compared with the magnetic card. A multi-purpose IC card is expected to spread as the card that overcomes the cost problem. One IC card can be used for a plurality of purposes such as the credit card, the cash card, the electronic money and the ID card. That can reduce the cost per purpose.
In case the IC card is for a plurality of uses, applications for the respective uses are stored in non-volatile memory such as EEPROM (Electrically Erasable Programmable Read Only Memory) mounted on an IC chip loaded on the IC card.
The respective applications work on CPU (Central Processing Unit) mounted on the IC chip and communicate with external devices such as a card reader-writer utilizing the communication interface on the IC card and sends and receives data, holds individual authentication, or the like.
Communication interfaces mounted on the IC card can be broadly classified into the contact-type interface and the non-contact-type interface.
The contact-type interface brings a contact point on the card into contact with the external device and communicates through its contact point. On the other hand, the non-contact-type interface gets into wireless communication with the external device through an antenna provided on the card. Either of the interfaces is used not only for communication but also for receiving power from the external device.
Many of the IC cards for a plurality of uses are usually the so-called combination cards on which both the contact-type interface and the non-contact-type interface are mounted.
That is because which of the communication interfaces is suitable depends on use in many cases. For example, if the IC card mounted with the contact-type interface is used as commutation ticket, the contact point frequently comes into contact with the external device. And there is fear that the contact point will wear out until communication is impossible. For the commutation ticket, therefore, the IC card mounted with the non-contact-type interface is preferable. For uses such as a cash card, on the other hand, the IC card mounted with a contact-type interface is preferable because the frequency of communication with external device is low as compared with the commutation ticket and is effective in preventing tapping.
Therefore, there is a great necessity that the IC card for a plurality of uses should be mounted with the both types of the interface.
In case a combination card is used as an IC card for a plurality of uses, communication interfaces used by applications are preset for the respective applications to match with communication interfaces utilized for the respective uses.
For example, the application that makes the IC card function as the commutation ticket uses the non-contact-type interface as the communication interface while the application that makes the IC card function as the cash card uses the contact-type interface as the communication interface.
As set forth above, which of the communication interfaces is suitable can depend on use. Therefore, the communication interface utilized by application is preset to the contact-type interface or non-contact-type interface. But either of the interfaces has both advantages and disadvantages.
The non-contact-type interface is relatively high in communication speed and also is highly easy of maintenance. Another advantage is that one external device can communicate with a plurality of IC cards simultaneously. On the other hand, the non-contact-type interface has a shortcoming. That is, the communication is wireless and there is fear of security such as tapping. Meanwhile, the contact-type interface has such shortcomings as relatively low communication speed and less easy maintenance, but has an advantage with regard to security.
Therefore, even if the communication interface to be used by application is preset to either of the interfaces according to use, the advantages the respective interfaces have can not be made full use of.
For example, of the non-contact-type interfaces, the proximity-type interface is not much more than 106 kbps in communication speed, while the contact-type interface is not much more than 9.6 kbps in communication speed. In case an IC card is used as the cash card, priority is given to prevention of tapping or the like and the contact-type interface is used. Yet, it is not desirable to sacrifice the communication speed.
Such a problem comes up with not only the IC card but also other electronic devices that have a contact-type interface and a non-contact-type interface as the communication interface for communication with external devices.